Process for preventing stains in photographic color material by the use of a fixing bath-consisting of water, an alkali sulfite, and a fixing agent



Patented July 11, 1950 PROCESSYFORxPREVENTING STAINS IN PHD! TGGRAPHiC COLOR MATERIALBY THE PAT E'NT' o-FFi'cE USE or A FIXING BA'rac'oNsI-s'rm oF. WATER. AN ALKALI'SULFITE, AND'A Fix:

IN'G AGENT rim-slap. Harshand'JamesEnBates, Binghame ton, N.- Y-., assignors-to General Aniline .'& Film Corporation, New York, N. Y., a. corporation :of

Delaware No Drawing. Application December-3,4945;

SerialNo. 632,592

9 Claims.

This invention {relates to p'hotographic antistain baths,- to anti-stain baths employed in multicolor photography; and especially to non-staining baths for'the fixingof multi-co-lor photo graphic material following the bleaching treatment.

It is known that in the processing of multicolor reversible 'film and multi-color reversible white opaque, the exposed film'or exposedwhite opaque, is'first developed with a normal black and white developer to produce a negative image. After development, the'b'lack and white negative material, without being fixed, ,is exposed to general illumination, followed by a second development with a color-forming developer. During the first and second development the silverhalides. in all'the layers are reduced tometallic silver. After the second development, the materialis cleared in running water, hardened in an aqueous solution consisting of either chrome or potassium alum, andthen washed inrunning water. Afterthe lattertre'atment, thesilver pres.- ent in all the layers formed'during the'first and second development'isconverted into a salt by any of the known silver-salt formers, commonly known as bleachingbaths, and the silver-salt thus formed is then removed by dissolving it in a silver-salt solvent-suchas, for example, hypo. The material is ithenxwashed fora .long period. of time and then dried.

Prior to the washing operation it is essential that the residual second or color developer and bleach solutions .be removed,. otherwise stains-will be formed during thewashing-and dryingoperations, which areparticularly noticeable in the white area. In order to prevent thisstaining, an extended final washing. time in, running water of from fifteen minutes to two hours, has been proposed. Even if this proposal be adoptedstains areneverthelessformed during the long washing operation, which makes it imperative to keep the washing time as shortas possible. However, if washingtimes arereduced so. that thestaining iskept to aminimum, the chemicals will not be eliminated fromthe emulsion layers and stains will form during drying. Itis believed that the staining resultsfrom the oxidation of traces=of the color developer retained inlthelayersof the material followingcolor-forming;development, when-then reactwith the unusedcolor-former.

An object of thepresentinvention isto permit norm-a1 washing time of color developed multi-. color photographic material while preventing the formation of stain.

Another object is ..-toperm-it. a shorter washing time than .is .normally :required; while preventing. staining-during boththe final washing and drying operations.

A further object ofthe invention is a fixing bath which clears: undesirable matter from: a multi-colorphotographic material ina short-time while 1 avoiding I staining;

Other; objectsland'features .of the invention .will become.- more. apparent. asthe. description pro,- ceeds.

We have found tha-t;.th'eaboveyob-jects are :aoe complishe'd'i by employing, as a: fixing bath, .an aqueous solution; containing hypo lrsuchx as monium :thiosulfate: onsodium thiosulfate; andsa water soluble alkaltsulfite: such asammonium; potassium or; sodium: sulfite; bisulfite, andmeta bisulfite. This discovery,makes it possible to considerably reduce the fi'rialwashing time. The concentrationof liypomay-vary 'from gramsto 3oOg-ramsper liter: of water; The concentration of the water-solublealkali sulfite may-vary'from'l gram to as high as-"20 grams per'liter; The'concentration of-the hypo and the alkali sulfite should be so adjusted that the p'I-I of the resulting solution is not lower than a pH of-"Gill. Amounts oflalkali sulfite-.-highers than 20 grams per liter give-little improvement in stain prevention from a practical standpoint and, accordingly. .con centrations ranging from between 1.to 15 grams per liter are most desirab le.-

The photographic multi layerlmaterials; W-hifih may be processed with the anti+stain bathzofthe present'invention, are color reversible-film, color negative film,..co1or reversible white opaque, and color paper irrespective of. whether. the dyestufi images are produced'with the color-formers incorporated'in the. emulsion or by a. selective. second exposure and color development wherein the color-formers. are addedt'o the developing solu: tion. Thescolor, reversible film consistseofian in--. tegraltripack. emulsion coated on the usual 5 clear. cellulose-acetate or. nitrate ,filmrbase; Each .of 'the emulsions aresensitizedto. one I of: the; primary colors. of; light; namely,. blue,. green, and. red: The topilayer. isbluesensitive; Airfilter layer,

, p-Monomethylamine-m-phenol sulfate 3 yellow in color and blue absorbing, lies under the top layer. Below this filter layer, lies a green sensitive emulsion layer, and below this is a red sensitive emulsion layer. Each of the three silverhalide emulsion layers contain dye-forming compounds which unite during the development of silver image in an aromatic amine developing agent to form a'dye with the oxidation product of the developing agent, or may be free from colorformers in which case the film is processed with the color-formers in the color developers by the selective second exposure and color development method as described in United States Patents 1,897,866; 1,900,870; 1,928,709 and 1,980,941. The color negative film is made up in the same manner as the color reversible film, with the exception that it may contain a layer of clear gelatin between the red sensitive layer and the green sensitive layer. The color reversiblewhite opaque material is prepared in the same manner as color reversible film and the color negative film, with 1 the exception that the base consists of an opaque in a bleach, followed by treatment in a bath of sodium thiosulfate according to usual practice.

A yellow dye is formed in the blue sensitive emulsion; a magenta dye is formed in the green sensitive emulsion; and a cyan dye is formed in the red sensitive emulsion. Combinations of these three printing primaries will produce all of the other colors in the finished film or print. Suitable methods for the preparation of photographic multilayer materials havebeen described in the literature relating to color photography, and'are, therefore, not-described here. 1

' The following examples describe in detail methods for accomplishing the above objects, but it is to' be understood that they are inserted merely for the purpose of illustration and are not to be construed as limiting the scope of the invention.

. Example 'I g A 4" x 5" full color transparency sheet of color film was printed by contact on two 4" x 5" sheets of color reversible white opaque film.

- The two sheets of 4"- x 5" color reversible white opaque film were first developed for twelve minutes at 68 F. in a developer of the following composition:

grams 8 Sodium sulfite do Hydroquinone do 6 Sodium carbonate (monohydrate) do 40 Sodium thiocyanate do i 2 Potassium bromide ..do 2 Water to make up liter 1 Short stopped for 3 minutes at 68 F., in a 5% aqueous solution of sodium bisulfite.

Washed for 2 minutes in running water at 68 F. Color developed for 15 minutes at 68 F., in a developer of the following composition:

p-Aminodiethylaniline H01 grams .4 Sodium sulfite do 5 Hydroxylamine HCl do 2 Sodium carbonate do 40 Potassium bromide do- 1 Water to make up liter 1 Rinsed for 4 minutes in running water at 68 F.

Hardened for 5 minutes in a 3% aqueous solution of potassium chrome alum.

Washed for 5 minutes in running water at 68 F. The washed material was then treated with a bleach bath of the following composition:

Di-potassium mono-sodium ferricyanide grams Potassium bromide do 15 Disodium phosphate do 40 Sodium bisulfate do 25 Formalin (40%) co 20 Water to make up liter 1 Washed for 5 minutes at 68 F.

The first washed film was fixed in solution No. 1 and the second washed film was fixed in solution No. 2 of the following compositions:

No. 1 No. 2

Sodium fninsnlfafe rams 200 200 Sodium sulfite do 5 Water to make up liters l 1 yv tion No. 1 showed even greater highlight stains,

while the film fixed in solution 2 containing sodium sulfite did not change.

Example II in solution No. 1 showed objectionable stains after washing and drying, while the print fixed in solution No. 2 containing sodium bisulfite after washing and drying was clear and unstained.

Example III Example I was repeated with the exception that the fixing solution No. 2 contained 3 grams of sodium metabisulfite instead of sodium sulfite. After fixing, washing and drying, the color print fixed in solution No. 1 showed objectionable stains, while the print fixed in solution No. 2 containing sodium metabisulfite was clear and unstained.

From the above examples, it is manifest that multilayer photographic material fixed in an ordi nary hypo solution shows marked staining after washing and drying of said material. This staining occurs especially under slow drying conditions and is probably due to the coupling of the slow. oxidation product of the color developer with a residual color coupler present in one or more layers.

It will be understood that where in the claims appended hereto the term hypo is used, that such is intended to include ammonium thiosulfate.

This application is a continuation-in-part of our co-pending application Serial No. 627,533, filed on November 8, 1945, now Patent No. 2,475,134, July 5, 1949.

The above specific examples are to be regarded as merely illustrative of the invention, and not in any sense restrictive. It will be obvious to anyone skilled in the art that many modifications such as substituting equivalent material and varying the proportions of materials used are within the spirit and scope of the invention as defined in the appended claims.

We claim:

1. In the process of color photography, the method of preventing stains on color images selected from the class consisting of indophenol and azomethine dyes produced in multilayer color film by color forming development which comprises fixing said film after exposure, color development, and bleaching with an aqueous solution consisting of water, an alkali sulfite, and a fixing agent of the group consisting of ammonium thiosuliate and sodium thiosulfate, and thereafter Washing and drying the fixed film.

2. In the process of color photography, the method of preventing stains on color images selected from the class consisting of indophenol and azomethine dyes produced in multilayer color film by color forming development which comprises fixing said film after exposure, color development, and bleaching with an aqueous solution consisting of water, sodium sulfite, and a fixing agent of the group consisting of ammonium thiosulfate and sodium thiosulfate, and thereafter washing and drying the fixed film.

3. In the process of color photography, the method of preventing stains on color images selected from the class consisting of indophenol and azomethine dyes produced in multilayer color film by color forming development which comprises fixing said film after exposure, color development, and bleaching with an aqueous solution consisting of water, sodium bisulfite, and a fixing agent of the group consisting of ammonium thiosulfate and sodium thiosulfate, and thereafter washing and drying the fixed film.

4. In the process of color photography, the method of preventing stains on color images selected from the class consisting of indophenol and azomethine dyes produced in multilayer color film by color forming development which comprises fixing said film after exposure, color development, and bleaching with an aqueous solution consisting of water, sodium metabisulfite, and a fixing agent of the group consisting of ammonium thiosulfate and sodium thiosulfate, and thereafter washing and drying the fixed film.

5. The method according to claim 1, wherein the concentration of the said alkali sulfite ranges from 1 to 20 grams per liter.

6. In a process of producing color photographic images selected from the class consisting of indophenol and azomethine dyes in a multilayer color film by exposing the film, color developing the same, bleaching, and washing, the improvement which comprises avoiding the formation of stain, after the bleaching and washing operation, by fixing the said film with an aqueous solution consisting of water, an alkali sulfite, and a fixing agent of the group consisting of ammonium thicsulfate and sodium thiosulfate, and thereafter washing and drying the fixed film.

7. In a process of producing color photographic images selected from the class consisting of indophenol and azomethine dyes in a multilayer color film by exposing the film, color developing the same, bleaching, and washing, the improvement which comprises avoiding the formation of stain, after the bleaching and washing operation, by fixing the said film with an aqueous solution consisting of water, sodium sulfite, and a fixing agent of the group consisting of ammonium thiosulfate and sodium thiosulfate, and thereafter washing and drying the fixed film.

8. In a process of producing color photographic images selected from the class consisting of indophenol and azomethine dyes in a multilayer color film by exposing the film, color developing the same, bleaching, and washing, the improvement which comprises avoiding the formation of stain, after the bleaching and washing operation, by fixing the said film with an aqueous solution consisting of water, sodium bisulfite, and a fixing agent of the group consisting of ammonium thiosulfate and sodium thiosulfate, and thereafter washing and drying the fixed film.

9. In a process of producing color photographic images selected from the class consisting of indophenol and azomethine dyes in a multilayer color film by exposing the film, color developing the same, bleaching, and washing, the improvement which comprises avoiding the formation of stain, after the bleaching and washing operation, by fixing the said film with an aqueous solution consisting of water, sodium metabisulfite, and a fixing agent of the group consisting of ammonium thiosulfate and sodium thiosulfate, and thereafter washing and drying the fixed film.

HAROLD C. HARSI-I. JAMES E. BATES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,521,840 Sheppard Jan. 6, 1925 1,544,936 Punnett July 7, 1925 1,753,059 Murray Apr. 1, 1930 1,976,301 Seymour et a1 Oct. 9, 1934 2,059,884 Mannes Nov. 3, 1936 2,063,297 Crabtree et al Dec. 8, 1936 2,203,903 Ham June 11, 1940 2,323,481 McQueen July 6, 1943 2,384,658 Vittum Sept. 11, 1945 2,414,491 Tulagin Jan. 21, 1947 OTHER- REFERENCES Clerc, Photography Theory and Practice, 2d edition, 1937, published by Sir Isaac Pitman & Sons Ltd., pages 236 and 237 cited 

1. IN THE PROCESS OF COLOR PHOTOGRAPHY, THE METHOD OF PREVENTING STAINS ON COLOR IMAGES SELECTED FROM THE CLASS CONSISTING OF INDOPHENOL AND AZOMETHINE DYES PRODUCED IN MULTILAYER COLOR FILM BY COLOR FORMING DEVELOPMENT WHICH COMPRISES FIXING SAID FILM AFTER EXPOSURE, COLOR DEVELOPMENT, AND BLEACHING WITH AN AQUEOUS SOLUTION CONSISTING OF WATER, AN ALKALI SULFITE, AND A FIXING AGENT OF THE GROUP CONSISTING OF AMMONIUM THIOSULFATE AND SODIUM THIOSULFATE, AND THEREAFTER WASHING AND DRYING THE FIXED FILM. 